354 BOTANICAL GAZETTE [april 



out by comparing the curves for table II A and II B as given in 

 fig. 2. The ordinates represent relative amount of respiration 

 (curve A, table II A), relative rate of respiration (curve C, table 

 II A), net resistance as percentage of that at the start (curve B, 

 table II B) respectively (unbroken Hues). The relative rate and 

 relative amount of respiration at the end of over 2 . 5 hours are still 

 much above the normal even though the measurements of electrical 

 resistance have shown the tissue to be dead before 100 minutes. 



REL.RATEOFRESP. 

 %REST. REL.AMT-OFRESP. 



60 120 MINUTES 



Fig. 2. — Curves showing effect produced by sea water containing 17.4 per cent 

 (by volume) of acetone upon relative amount and relative rate of respiration, and 

 effect produced by sea water containing 16. 2 per cent of acetone upon net electrical 

 resistance of Laminaria: curve A, ordinates represent relative amount of respiration; 

 curve B, ordinates represent net resistance as percentage of that at start; curve C, 

 ordinates represent relative rate of respiration (unbroken hnes) ; controls in sea water 

 (broken hnes); each control curve bears same S3rmbol and letter (with a prime) as 

 experimental curve; abscissae represent time in minutes. 



Table III A shows the effect produced by sea water containing 

 24.2 per cent (by volume) of ethyl alcohol (made up to conduc- 

 tivity of sea water by the addition of concentrated sea water). 

 In fig. 3 the ordinates represent: relative amount of respiration 

 (curve A, table III A), relative rate of respiration (curve C, 

 table III A), net resistance as percentage of that at the start 

 (curve B, table III B) respectively (unbroken lines). If we con- 

 sider the material dead at the end of 90 minutes, we find that the 



